Relatability is certainly a key component of Knocked Up «s inherent appeal, as it plunders
for humor that most nightmarish of singles» fears, unwanted pregnancy, via the story of Alison (Katherine Heigl) and Ben (Seth Rogen), a mismatched twosome whose
polar - opposite lives are accidentally entwined by a drunken one -
night stand that, due to miscommunication over use of a condom (the momentous phrase in question being «Just do it already!»)